/**
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jivesoftware.smackx.bytestreams.socks5;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.jivesoftware.smack.PacketListener;
import org.jivesoftware.smack.filter.AndFilter;
import org.jivesoftware.smack.filter.IQTypeFilter;
import org.jivesoftware.smack.filter.PacketFilter;
import org.jivesoftware.smack.filter.PacketTypeFilter;
import org.jivesoftware.smack.packet.IQ;
import org.jivesoftware.smack.packet.Packet;
import org.jivesoftware.smackx.bytestreams.BytestreamListener;
import org.jivesoftware.smackx.bytestreams.socks5.packet.Bytestream;

/**
 * InitiationListener handles all incoming SOCKS5 Bytestream initiation
 * requests. If there are no listeners for a SOCKS5 bytestream request
 * InitiationListener will always refuse the request and reply with a
 * &lt;not-acceptable/&gt; error (<a
 * href="http://xmpp.org/extensions/xep-0065.html#usecase-alternate"
 * >XEP-0065</a> Section 5.2.A2).
 * 
 * @author Henning Staib
 */
final class InitiationListener implements PacketListener {

	/* manager containing the listeners and the XMPP connection */
	private final Socks5BytestreamManager manager;

	/* packet filter for all SOCKS5 Bytestream requests */
	private final PacketFilter initFilter = new AndFilter(new PacketTypeFilter(
			Bytestream.class), new IQTypeFilter(IQ.Type.SET));

	/* executor service to process incoming requests concurrently */
	private final ExecutorService initiationListenerExecutor;

	/**
	 * Constructor
	 * 
	 * @param manager
	 *            the SOCKS5 Bytestream manager
	 */
	protected InitiationListener(Socks5BytestreamManager manager) {
		this.manager = manager;
		initiationListenerExecutor = Executors.newCachedThreadPool();
	}

	public void processPacket(final Packet packet) {
		initiationListenerExecutor.execute(new Runnable() {

			public void run() {
				processRequest(packet);
			}
		});
	}

	private void processRequest(Packet packet) {
		Bytestream byteStreamRequest = (Bytestream) packet;

		// ignore request if in ignore list
		if (this.manager.getIgnoredBytestreamRequests().remove(
				byteStreamRequest.getSessionID())) {
			return;
		}

		// build bytestream request from packet
		Socks5BytestreamRequest request = new Socks5BytestreamRequest(
				this.manager, byteStreamRequest);

		// notify listeners for bytestream initiation from a specific user
		BytestreamListener userListener = this.manager
				.getUserListener(byteStreamRequest.getFrom());
		if (userListener != null) {
			userListener.incomingBytestreamRequest(request);

		} else if (!this.manager.getAllRequestListeners().isEmpty()) {
			/*
			 * if there is no user specific listener inform listeners for all
			 * initiation requests
			 */
			for (BytestreamListener listener : this.manager
					.getAllRequestListeners()) {
				listener.incomingBytestreamRequest(request);
			}

		} else {
			/*
			 * if there is no listener for this initiation request, reply with
			 * reject message
			 */
			this.manager.replyRejectPacket(byteStreamRequest);
		}
	}

	/**
	 * Returns the packet filter for SOCKS5 Bytestream initialization requests.
	 * 
	 * @return the packet filter for SOCKS5 Bytestream initialization requests
	 */
	protected PacketFilter getFilter() {
		return this.initFilter;
	}

	/**
	 * Shuts down the listeners executor service.
	 */
	protected void shutdown() {
		this.initiationListenerExecutor.shutdownNow();
	}

}
